WNTs play key roles in development and disease, signaling through Frizzled (FZD) seven-pass transmembrane receptors and numerous co-receptors including ROR and RYK family receptor tyrosine kinases (RTKs). We describe crystal structures and WNT-binding characteristics of extracellular regions from the Drosophila ROR and RYK orthologs Nrk (neurospecific receptor tyrosine kinase) and Derailed-2 (Drl-2), which bind WNTs though a FZD-related cysteine-rich domain (CRD) and WNT-inhibitory factor (WIF) domain respectively. Our crystal structures suggest that neither Nrk nor Drl-2 can accommodate the acyl chain typically attached to WNTs. The Nrk CRD contains a deeply buried bound fatty acid, unlikely to be exchangeable. The Drl-2 WIF domain lacks the lipid-binding site seen in WIF-1. We also find that recombinant DWnt-5 can bind Drosophila ROR and RYK orthologs despite lacking an acyl chain. Alongside analyses of WNT/receptor interaction sites, our structures provide further insight into how WNTs may recruit RTK co-receptors into signaling complexes. Display omitted •WNT-binding CRDs of ROR family receptors differ structurally from those in FZDs•The WIF domain of the RYK ortholog Derailed lacks WIF-1’s lipid binding site•Drosophila WNT-5 binds ROR and RYK family receptors despite lacking an acyl chain•WNT-binding receptor tyrosine kinases recognize different WNT features than FZDs Several receptor tyrosine kinase (RTK) family members function as WNT receptors. Shi et al. show that although RTKs bind WNTs using similar domains to those seen in Frizzleds (FZDs) and WIF-1, they bind WNTs in a distinct way that may allow a single WNT to bind both receptor types simultaneously.